Pressure exchanger



Feb. 15, 1966 n. B. SPALDING PRESSURE EXCHANGER Filed Nov. 6, 1963 3Sheets-Sheet 1.

D. B. SPALDING PRESSURE EXCHANGER Feb. 15, 1966 3 Sheets-Sheet 2 FiledNov. 6, 1963 Feb. 15, 1966 V D. B. SPALDING 3,234,736

PRESSURE EXCHANGER Filed Nov. 6, 1963 3 Sheets-Sheet 5 United StatesPatent PRESSURE EXCHANGER Dudley Brian Spalding, 2 Vineyard Hill Road,Wimbledon, London, England Filed Nov. 6, 1963, Ser. No. 321,762 Claimspriority, application Great Britain, Nov. 15, 1962, 43,336 62 14 Claims.(Cl. 60-39.45)

The present invention relates to pressure exchangers and to gas turbineor like plant in which a pressure exchanger serves as a combustion meansfor the plant.

The term pressure exchanger is used herein to mean apparatus includingcells in which one gas quantity expands so compressing another gasquantity with which it is in direct contact, ducting to lead gas atdifferent pressures steadily to and from the cells and means to effectrelative motion between the cells and the ducting. The cells arearranged around a cell rotor in the form of a ring.

According to the present invention a pressure exchanger includes a cellring, a cell rotor, a plurality of walls arranged around the rotor todefine a plurality of open-ended cells, the cell rotor and the wallsforming parts of the cell ring, means to introduce fluid to the cells,means to extract fluid from the cells, means to effect rotation of thecell ring, end-plates positioned one adjacent each end of the cell ring,at least one of the endplates having a port for the admission of fluidto the cells and a port for the extraction of fluid from the cells, oneof which points is positioned in the end-pla=te immediately to followthe other in the direction of rotation of the cell ring, ducting toprovide communication between the two ports, and fuel injection meansinterposed in the ducting. In operation, the direction of fluid flowthrough the ducting may be generally opposite to the direction ofrotation of the cell ring.

Each end-plate may include a pair of ports comprising a point for \theadmission of fluid to the cell-s and a port for the extraction of fluidfrom the cells, each pair of ports having one port positionedimmediately to follow the other in the direction of rotation of the cellring. Ducts are then provided to permit communication between the twoports of each pair of ports and fuel injection means is interposed inone or both of the ducts.

The two ports in one end-plate may :be disposed directly opposite thetwo ports in the other end-plates.

The pressure exchanger in accordance with the invention may beinterposed between a turbine and a compressor of a gas turbine plant.

Embodiments of the invention will now be described with reference to theaccompanying diagrammatic drawings in which:

FIGURE 1 is an exploded perspective view of a pressure exchanger inaccordance with the invention;

FIGURE 2 is a developed view of the pressure exchanger illustrated inFIGURE 1, the cell walls of the pressure exchanger being omitted for thesake of clarity;

FIGURES 3, 4 and 5 are developed views of further pressure exchangerembodiments in accordance with the invention, the cell walls of thepressure exchangers again being omitted for the sake of clarity;

FIGURE 6 is a fragmentary end view of a pressure exchanger cell ringincluding cells of honeycomb construction; and

FIGURE 7 shows a pressure exchanger according to the invention includedin a gas turbine plant.

In each of the embodiments to be described, structure for effecting onlyone cycle of operation has been shown and described. In practice, itwould normally be desirable to construct the pressure exchanger formultiple cycle operation.

3,234,736 Patented Feb. 15, 1966 Referring now primarily to the explodedperspective view of FIGURE 1, it will be appreciated that for the sakeof clarity the number of cell walls shown is smaller than would be usedin practice. The pressure exchanger includes a cell ring having aplurality of radial walls 1 arranged around a cell rotor 2 and having acylindrical shroud 3. The cells defined by the walls 1, the cell rotor 2and the shroud 3 are open-ended but the effective opening and closing ofthe ends of the cells are controlled by end-plates 4 and 5, onepositioned at each end of the cell ring. The end-plate 4 has a port 6 tolead gas to the cells of the pressure exchanger and ports 7 and 8 tolead gas from the cells. The end-plate 5 has a port 9 to lead air to thecells. The port 6 communicates with one end of a duct 10, the other endof the duct 10 communicating with the port 7. Ducts 11 and 12communicate with the ports 8 and 9 respectively. Although the ducts 11and 12 are necessary for certain applications, it is to he understoodthat when a pressure exchanger as shown in this figure forms part of ajet propulsion plant, then these ducts may be omitted. A fuel injectionnozzle 13 and an igniter 14 are disposed in the duct 1%. A shaft (notshown) passes through bores 15, 16 and 17 in the rotor 2 and theend-plates 4 and 5.

The ports 8 and 9 together with the cells at any one time incommunication with these ports constitute a scavenging stage for thepressure exchanger. The endplate 5 is shown with a port 9 which occupiesonly a minor proportion of the circumferential extent of the end-plate.In practice, it is desirable that this port should be considerablylarger than illustrated in order to avoid restriction of flow throughthe pressure exchanger. The ports 6 and 7 should, in practice, occupy aslittle as is practical of the circumferential extent of the end-plate 4.

FIGURE 2 shows a developed view of the pressure exchanger illustrated inFIGURE 1, the cell walls 1 being omitted for the sake of clarity.

In operation, the cells of the cell ring are continuously moving pastthe ports and the lands between the ports in the direction indicated byarrow A, and for the purpose of description the cycle may be consideredto start at any position.

Assuming that the cycle starts at a position X (FIG- URE 2), the cell atthis position contains combustion gases, indicated by a series ofparallel lines, a mixture of combustion gases and air, indicated bycross-hatched lines, and air, indicated by that part of the cell ringleft blank. As the cell continues to rotate, continued mixing of thecombustion gases and the fresh air takes place. On continued rotation,the cell is opened at its left-hand end, as shown in FIGURE 2, to theoutlet port 7. Since the gas in the cell is at a higher stagnationpressure than the stagnation pressure existing in that part of the duct1% adjacent the port 7, expansion waves and reflected expansion waves,diagrammatically represented at 18, 19 by broken lines respectively willpass through the cell as the combustion-supporting mixture of combustiongases and air in the cell pass through the port 7 into the duct 10. Thenozzle 13 continuously injects fuel into the gases passing through theduct 10, and the combustible mixture is initially ignited by the igniter14. However, during steady running the igniter need not be operative. Oncontinued rotation, the cell becomes closed to the port 7 by theend-plate tand is then opened, again by the end-plate 4, to thescavenging stage outlet port 8 which communicates with the duct 11.Mixed combustion gases and air pass out of the cell and into the duct11. The stagnation pressure of the gas originally in the duct 11 islower than the initial stagnation pressure of the contents of the cell.Consequently, expansion waves of small amplitude, diagrammaticallyrepresented at 29 by a broken line, will pass through the cell thuscreating a lowpressure region at the right-hand end of the cell. As thecell ring continues to rotate, the cell is opened by the end-plate tothe scavenging stage inlet port 9 through which air is admitted to thecell via the duct 12. On con tinued rotation of the cell ring, the cellis closed by the end-plate 4 and a compression wave, diagrammaticallyrepresented at 21 by a full line, will pass through the cell thuscompressing the contents of the cell. The static pressure at the outletport 8 is the same or lower than the static pressure at the inlet port9. However, the stagnation pressure at the outlet port 8 will be higherthan, or at least equal to, the stagnation pressure at the inlet port 9in consequence of the increased velocities of the gases leaving throughthe port 8. As the cell ring continues to rotate, the cell is opened bythe end-plate 4 to the inlet port 6 which forms a termination of theduct and the high-pressure combustion gases pass into the cell. Thegases in the duct 16 are at a higher pressure than the air in the cell,consequently, a compression wave and a reflected compression wave,diagrammatically represented at 22 and 23 respectively by full lines,will pass through the cell thus compressing the contents of the cell. Asthe cell continues to rotate, the cell becomes closed at both ends bythe end-plates 4, 5 and then once agin reaches the position X. The cycleof operation is thereafter continuously repeated during operation of thepressure exchanger.

FIGURE 3 shows a pressure exchanger arrangement similar to thatdescribed in accordance with FIGURES 1 and 2 and like integers have thesame reference numerals. In this figure the pressure exchanger includesadditional ports 6A and 7A in the end-plate 5, and a duct IIPA whichcommunicates at its ends with the ports 6A and 7A. A fuel injectionnozzle 13A and igniter 14A are positioned in the duct 10A. The ports 6Aand 7A and the duct 10A correspond as regards position and purpose tothe ports 6 and 7 in the end-plate 4, and the duct ll) respectively. Theport 6A lies directly opposite the port 6 and the port 7A directlyopposite the port 7.

The operation is, in general, similar to that of the FIG- URE 2embodiment. Air is admitted to the cells through the port 9 and iscompressed by combustion gases admitted to the cells through the ports 6and 6A. The air then mixes with the combustion gases during that part ofthe cycle of operation when the cells are closed at both ends by theend-plates 4, 5. When the cells are opened to the ports 7 and 7A themixture of combustion gases and air enters the ducts 10 and NArespectively. Fuel is continuously injected into the mixture by thenozzle 13A and the combustible mixture is initially ignited by theigniter 14A. The mixed gases are expelled from the cells through thescavenging stage outlet port 8 into the duct 11.

Referring now to the embodiment of FIGURE 4, in which like integers tothose previously described have the same reference numerals, theend-plate 4 includes the scavenging stage outlet port 8, a port 25 forthe extraction of a mixture of combustion gases and air, and ofcombustion gases from the cells and a port 26 for the admission of thesegases to the cells. The port 26 is of larger circumferential extent thanthe port 25, for example, in the order of the ratio 3:1. A duct 27communicates at its ends with the ports 25 and 26. The end-plate 5includes the scavenging stage inlet port 9, a port 28 to lead combustiongases to the cells, and a port 29, of larger circumferential extent thanthe port 28, to lead combustion-supporting gases and combustion gasesfrom the cells. A duct 30 connects the ports 28 and 29. The inlet port28, the outlet port 25 and cells at any given time in communication withthese ports together constitute a scavenging stage. The inlet port 26,the outlet port 29 and cells at any given time in communication Withthese ports together form another scavenging stage.

A fuel injection nozzle 31 and a fuel igniter 32 are provided within theduct 30.

In operation, fresh air admitted to the cells through the port 9 ismixed with combustion gases entering the cells through the port 28. Themixed gas together with a quantity of combustion gases leave the cellsthrough the port 25 and enter the duct 27 in which further mixing of thegases takes place. The direction of flow in the duct 27 is in generalthe same as the direction of motion of the cells of the cell ring. Thismay be explained as follows. If the embodiment of FIGURE 4 did notinclude the duct 27 and associated ports then a compression wave wouldbe reflected from the end-plate surface occupying the notional positionof the outlet port 25 and the pressure there would be higher than thepressure in the cells at the notional position of the inlet port 26.This pressure difference arises because an expansion wave set up by theopening edge of the outlet port 29 gives rise to a pressure drop in thecell at a position between the opening and closing edges of the notionalinlet port 26, whereas a compression wave is set up by the opening edgeof the port 28 which gives rise to a pressure increase in a cell justarriving at the opening edge of the notional outlet port 25. Whenhowever, the ports 25 and 26 are physically present, then because of thepressure difference across the expansion wave at the port 26 there is adrop in pressure at the downstream part of the port 26 (considered inthe direction of motion of the cells) and this pressure difference iscommunicated to the upstream part. Thus, because of the pressuredifference between the two ports there is a gas flow from the port 25 toport 26. Consequently, the mixed gases together with any combustiongases enter the cells through the inlet port 26. Thecombustion-supporting gases are then admitted by r the port 29 to theduct in which combustion is effected.

Finally, the mixed gases are expelled from the cells through thescavenging stage outlet port 8.

If desired, baflles (not shown) may be disposed in the duct 27 in orderto increase the rate of mixing between the fresh air and the combustiongases. It is further possible to vary the eflect of these baffles duringoperation of the pressure exchanger.

In order to increase further the rate of mixing a feedback loop 33(indicated by broken lines) may connect the duct 30 just upstream of theinlet port 28 to the duct 12 just upstream of the inlet port 9.

FIGURE 5 shows a pressure exchanger in which the end-plate 4 includesthe scavenging stage outlet port 8, a port 35 for the extraction ofcompressed air from the cells and a port 36 for the admission of amixture of combustion gases and air to the cells. A duct 37 communicatesat its ends with the ports 35 and 36 and a flame tube 38 is mountedwithin the duct 37 with its outlet adjacent the port 36. The flame tube38 is required within the duct 37 because there is only pure relativelycold air present in that duct. The flame tube of conventional designsets up requisite vortices to ensure stable combustion. The end-plate 5includes the scavenging stage inlet port 9, a port 39 to lead compressedair to the cells and a port 40 for the extraction of compressed air fromthe cells. A duct 41 communicates at its ends with the ports 39 and 40.The inlet port 39, the outlet port 35 and cells at any given time incommunication with these ports together constitute a scavenging stage.Similarly, the inlet port 36, the outlet port 40 and the cells at anygiven time in communication with these ports constitute anotherscavenging stage.

In operation, air entering the cells through the port 9 is compressed bycompressed air admitted through the port 39, and enters the duct 37 viathe outlet port 35. Part of the compressed air passing through the duct37 supports combustion in the flame tube 38 and the remainder of the airis thoroughly mixed with the combustion products from the flame tubebefore being admitted to the cells through the port 36. The mixed gasesentering the cells through the port 36 serve to compress the air alreadyin the cells, which compressed air leaves the cells through the port 40.The mixed gases are finally expelled from the cells through thescavenging stage outlet port 8.

The duct 41 may have a tapping connected to a duct through whichrelatively cool fresh air can be supplied to hot parts of the pressureexchanger or to hot parts of an associated gas turbine plant,

It will be appreciated that in all of the embodiments hereinbeforedescribed, the stagnation pressure of gases leaving the cells throughthe outlet port 8 is higher than, or at least equal to, the stagnationpressure of the air admitted through the port 9. A pressure risetherefore exists between air admitted to the cells and gas extractedfrom the cells of the pressure exchanger combustion arrangement of theinvention. This is in direct contrast to the pressure loss inherent inconventional combustion arrangements.

FIGURE 6 shows a fragmentary end view of a cell ring of a pressureexchanger having cells of honeycomb construction. It will be seen thatthe cells defined by the walls 1, the hub 2 and the shroud 3 includecorrugated strips 42 which are brazed to the cell Walls 1 to give ahoneycomb configuration. Such a configuration will strengthen the cellwalls which is desirable since the walls will be subjected to highdifferential pressures during operation of the pressure exchanger.

FIGURE 7 shows a pressure exchanger in accordance with the inventionserving as the combustion means of a jet propulsion plant. The pressureexchanger receives compressed gases from a compressor 43 and deliverscombustion gases to a turbine rotor blade row 44 via inlet guide blades45. The compressor, the pressure exchanger and the turbine areco-axially mounted upon a shaft 46. The pressure exchanger rotor wouldnormally rotate independently of the compressor and turbine rotors. Ascan be seen from FIGURE 7 a proportion of the compressed air from thecompressor 43 bypasses the pressure exchanger cells in order to cool theoutside of the pressure exchanger rotor and to limit maximum temperatureat the entry to the turbine 44.

In each of the above described embodiments the ratio of the recirculatedcombustion gases to the fresh air is of the order of 4:1, but may behigher.

The rotor of the pressure exchanger may be driven by providing guidevanes at the inlet ports of the rotor or by skewing the vanes relativeto the axis of rotation. An electric motor may be provided for startingpurposes.

I claim:

1. A pressure exchanger including a cell ring, a cell rotor,a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, end-plates positionedone adjacent each end of the cell ring, at least one of the end-plateshaving a port for the admission of fluid to the cells and a port for theextraction of fluid from the cells, one of which ports is positioned inthe end-plate immediately to follow the other in the direction ofrotation of the cell ring, ducting to provide communication between thetwo ports, and fuel injection means interposed in the ducting.

2. A pressure exchanger as claimed in claim 1, in which, in operation,the direction of fluid flow through the ducting is generally opposite tothe direction of rotation of the cell ring.

3. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring end-plates positionedone adjacent each end of the cell ring, each end-plate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, each pair of portshaving one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in one of the ducts.

4. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming part-s of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, endplates positionedone adjacent each end of the cell ring, each end-plate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, each pair of portshaving one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in both of the ducts.

5. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, endplates positionedone adjacent each end of the cell ring, each end-plate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, the port for theadmission of fluid to the cells in one end-plate being disposed directlyopposite the port for the admission of fluid to the cells in the otherend-plate, the port for the extraction of fluid from the cells in theone end-plate being disposed directly opposite the port for theextraction of fluid from the cells in the other end-plate, each pair ofports having one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in one of the ducts.

6. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, end-plates positionedone adjacent each end of the cell ring, each endplate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, the port for theadmission of fluid to the cells in one end-plate being disposed directlyopposite the port for the admission of fluid to the cells in the otherend-plate, the port for the extraction of fluid from the cells in theone end-plate being disposed directly opposite the port for theextraction of fluid from the cells in the other end plate, each pair ofports having one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in both of the ducts.

7. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, endplates positionedone adjacent each end of the cell ring, each endplate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, the port for theadmission of fluid to the cells in one end-plate being disposed directlyopposite the port for the admission of fluid to the cells in the otherend-plate, the port for the extraction of fluid from the cells in theone end-plate being disposed directly opposite the port for theextraction of fluid from the cells in the other end plate, each pair ofports having one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in one of the ducts, the direction of fluid flow through theone duct being, in operation, generally opposite to the direction ofrotation of the cell ring.

8. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to effect rotation of the cell ring, end-plates positionedon one adjacent each end of the cell ring, each endplate having a pairof ports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, the port for theadmission of fluid to the cells in one end-plate being disposed directlyopposite the port for the admission of fluid to the cells in the otherend-plate, the port for the extraction of fluid from the cells in theone end-plate being disposed directly opposite the port for theextraction of fluid from the cells in the other end-plate, each pair ofports having one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, and fuel injection meansinterposed in both of the ducts, the direction of fluid flow throughboth of the ducts being, in operation, generally opposite to thedirection of rotation of the cell ring.

9. A pressure exchanger including a cell ring, a cell rotor, a pluralityof walls arranged around the rotor to define a plurality of open-endedcells, the cell rotor and the walls forming parts of the cell ring,means to introduce fluid to the cells, means to extract fluid from thecells, means to eflect rotation of the cell ring, end-plates positionedone adjacent each end of the cell ring, each endplate having a pair ofports comprising a port for the admission of fluid to the cells and aport for the extraction of fluid from the cells, each pair of portshaving one port positioned immediately to follow the other in thedirection of rotation of the cell ring, ducts to provide communicationbetween the two ports of each pair of ports, fuel injection meansinterposed in one of the ducts, and flame holding means disposed in theone duct.

10. A pressure exchanger including a cell ring, a cell rotor, aplurality of walls arranged around the rotor to define a plurality ofopen-ended cells, the cell rotor and the walls forming parts of the cellring, means to introduce fluid to the cells, means to extract fluid fromthe cells, means to effect rotation of the cell ring, end-platespositioned one adjacent each end of the cell ring, each endplate havinga pair of ports comprising a port for the admission of fluid to thecells and a port for the extraction of fluid from the cells, each pairof ports having one port positioned immediately to follow the other inthe direction of rotation of the cell ring, ducts to providecommunication between the two ports of each pair of ports, fuelinjection means interposed in one of the ducts, and baflies disposed inthe other of the ducts.

11. A pressure exchanger including a cell ring, a cell rotor, aplurality of walls arranged around the rotor to define a plurality ofopen-ended cells, which cells are of honeycomb construction, the cellrotor and the Walls forming parts of the cell ring, means to introducefluid to the cells, means to extract fluid from the cells, means toeffect rotation of the cell ring, at least one of the endplates having aport for the admission of fluid to the cells and a port for theextraction of fluid from the cells, one of which ports is positioned inthe end-plate immediately to follow the other in the direction ofrotation of the cell ring, ducting to provide communication between thetwo ports, and fuel injection means interposed in the ducting.

12. A gas turbine plant including a compressor, a turbine, and apressure exchanger, said pressure exchanger including a cell ring, acell rotor, a plurality of walls arranged around the rotor to define aplurality of openended cells, the cell rotor and the walls forming partsof a cell ring, means to introduce fluid to the cells, means to extractfluid from the cells, means to effect rotation of the cell ring,end-plates positioned one adjacent each end of the cell ring, at leastone of the end-plates having a port for the admission of fluid to thecells and a port fo the extraction of fluid from the cells, one of whichports is positioned in the end-plate immediately to follow the other inthe direction of rotation of the cell ring, ducting to providecommunication between the two ports, fuel injection means interposed inthe ducting, a duct to connect the compressor of the plant to said meansto introduce fluid to the cells of the pressure exchanger, and a duct toconnect said means to extract fluid from the cells of the pressureexchanger to the said turbine of the plant.

13. A gas turbine plant including a compressor, a turbine, and apressure exchanger, said pressure exchanger including a cell rotor, aplurality of walls arranged around the rotor to define a plurality ofopen-ended cells, the cell rotor and the walls forming parts of a cellring, means to introduce fluid to the cells, means to extract fluid fromthe cells, means to effect rotation of the cell ring, end-platespositioned one adjacent each end of the cell ring, each end-plate havinga pair of ports comprising a port for the admission of fluid to thecells and a port for the extraction of fluid from the cells, each pairof ports having one port positioned immediately to follow the other inthe direction of rotation of the cell ring, ducts to providecommunication between the two ports of each pair of ports, fuelinjection means interposed in one of the ducts, a duct to connect (thecompressor of the plant to said means to introduce fluid to the cells ofthe pressure exchanger, and a duct to connect said means to extractfluid from the cells of the pressure exchanger to the said turbine ofthe plant.

14. A gas turbine plant including a compressor, a turbine, and apressure exchanger, said pressure exchanger including a cell rotor, aplurality of Walls arranged around the rotor to define a plurality ofopen-ended cells, the cell rotor and the walls forming parts of a cellring, means to introduce fluid to the cells, means to extract fluid fromthe cells, means to effect rotation of the cell ring, endplatespositioned one adjacent each end of the cell ring, each end-plate havinga pair of ports comprising a port for the admission of fluid to thecells and a port for the extraction of fluid from the cells, each pairof ports having one port positioned immediately to follow the other inthe direction of rotation of the cell ring, ducts to provide communication between the two ports of each pair of ports, fuel injectionmeans interposed in both of the ducts, a duct to connect the compressorof the plant to said means to introduce fluid to the cells of thepressure exchanger, and a duct to connect said means to extract fluidfrom the cells of the pressure exchanger to the said turbine of theplant.

References Cited by the Examiner UNITED STATES PATENTS 1,515,101 11/1924Fowler 230 SAMUEL LEVINE, Primary Examiner,

1. A PRESSURE EXCHANGER INCLUDING A CELL RING, A CELL ROTOR, A PLURALITYOF WALLS ARRANGED AROUND THE ROTOR TO DEFINE A PLURALITY OF OPEN-ENDEDCELLS, THE CELL ROTOR AND THE WALLS FORMING PARTS OF THE CELL RING,MEANS TO INTRODUCE FLUID TO THE CELLS, MEANS TO EXTRACT FLUID FROM THECELLS, MEANS TO EFFECT ROTATION OF THE CELL RING, END-PLATES POSITIONEDONE ADJACENT EACH END OF THE CELL RING, AT LEAST ONE OF THE END-PLATESHAVING A PORT FOR THE ADMISSION OF FLUID TO THE CELLS AND A PORT FOR THEEXTRACTION OF FLUID FROM THE CELLS, ONE OF WHICH PORTS IS POSITIONED INTHE END-PLATE IMMEDIATELY TO FOLLOW THE OTHER IN THE DIRECTION OFROTATION OF THE CELL RING, DUCTING TO PROVIDE COMMUNICATION BETWEEN THETWO PORTS, AND FUEL INJECTION MEANS INTERPOSED IN THE DUCTING.
 12. A GASTURBINE PLANT INCLUDING A COMPRESSOR, A TURBINE, AND A PRESSUREXCHANGER, SAID PRESSURE EXCHANGER INCLUDING A CELL RING, A CELL ROTOR,A PLURALITY OF WALLS ARRANGED AROUND THE ROTOR TO DEFINE A PLURALITY OFOPENENDED CELLS, THE CELL ROTOR AND THE WALLS FORMING PARTS OF A CELLRING, MEANS TO INTRODUCE FLUID TO THE CELLS, MEANS TO EXTRACT FLUID FROMTHE CELLS, MEANS TO EFFECT ROTATION OF THE CELL RING, END-PLATESPOSITIONED ONE ADJACENT EACH END OF THE CELL RING, AT LEAST ONE OF THEEND-PLATES HAVING A PORT FOR THE ADMISSION OF FLUID TO THE CELLS AND APORT FOR